单选题   Almost 150 years after photovoltaic (光电的) cells and wind turbines (涡轮机) were invented, they still generate only 7% of the world's electricity. Yet something remarkable is happening. From being secondary to the energy system just over a decade ago, they are now growing faster than any other energy source and their falling costs are making them competitive with fossil fuels. BP, an oil firm, expects renewables to account for half of the growth in global energy supply over the next 20 years. It is no longer far-fetched to think that the world is entering an era of clean, unlimited and cheap power.
    There is a problem, though. To get from here to there requires huge amounts of investment over the next few decades. Normally investors like putting their money into electricity because it offers reliable returns. Yet green energy has a dirty secret. The more it is used, the more it lowers the price of power from any source. That makes it hard to manage the transition to a carbon-free future, during which many generating technologies, clean and dirty, need to remain profitable if the lights are to stay on. Unless the market is fixed, subsidies to the industry will only grow.
    Policymakers are already seeing this inconvenient truth as a reason to put the brakes on renewable energy. In parts of Europe, investment in renewables is slowing as subsidies are cut back. However, the solution is not less wind and solar. It is to rethink how the world prices clean energy in order to make better use of it.
    At its heart, the problem is that government-supported renewable energy has been imposed on a market designed in a different era. For much of the 20th century, electricity was made and moved by vertically integrated, state-controlled monopolies. From the 1980s onwards, many of these were broken up, privatized and liberalized, so that market forces could determine where best to invest. Today only about 6% of electricity users get their power from monopolies. Yet everywhere the pressure to decarbonize power supply has brought the state creeping back into markets. This is disruptive for three reasons. The first is the subsidy system itself. The other two are inherent to the nature of wind and solar, their intermittency and their very low running costs. All three help explain why power prices are low and public subsidies are addictive.
单选题     Why can photovoltaic cells and wind turbines compete with fossil fuels? ______
 
【正确答案】 B
【答案解析】由题干中的compete with fossil fuels定位至第一段第三句。 细节辨认题。第一段提到了太阳能电池和风力发电涡轮机美好的发展前景。尽管现在它们发的电只占全球发电量的7%，但是其发展势头比任何其他能源都要强劲，而且因为成本不断降低使它们能和化石燃料竞争，故答案为B。 [参考译文] 太阳能电池和风力发电涡轮机被发明以来的几乎150年后，它们仍然只能生产全球7%的电量。然而有些不同凡响的事情正在发生。就在10多年前，这两种能源还只能作为二级能源系统，但它们目前的发展势头比任何其他能源都要强劲，成本的不断降低也使它们能和化石燃料竞争。石油公司BP预期，可再生能源在未来20年将占全球能源供应增长量的一半。我们的世界正进入一个清洁、不受限且廉价的能源时代，这一想法已不再遥不可及。 但是有一个问题。要在未来几十年里完成这个转变需要大量的投资。投资者通常喜欢将钱投资到电力，因为它提供了可靠的回报。而绿色能源却有一个不让人喜欢的秘密。使用的绿色能源越多，就能更多地降低任何能源发电的电力价格。这使成功过渡到无碳未来变得很难。在此过程中，无论是用清洁或污染能源发电的技术公司想要正常运转都需要保持收益。除非市场被固定化，对这个行业的补贴只会不断增加。 政策制定者已经看到了这个棘手的事实，并以此作为理由来阻碍可再生能源。在欧洲部分地区，随着补贴的减少，对可再生能源的投资也减缓了。然而，解决方法不是少用风能和太阳能，而是重新思考为了更好地利用这些能源，全球该如何对绿色能源定价。 本质上来说，问题在于政府扶持的可再生能源被强加于一个市场上，而这个市场是在一个不同的时期设计的。20世纪的大部分时间里，电力是通过垂直一体化的国有垄断企业生产传输的。从20世纪80年代往后，许多国有企业解散、私有化和自主化，这样市场力量能决定最好往哪投资。如今，仅有6%的电力用户使用垄断企业的供电。而无处不在的电力供应脱碳的压力使得政府重新悄悄进入市场。由于三方面的原因，这会引发混乱。首先是补贴体系本身。另外两个原因跟风能和太阳能的本质有关：它们的间歇性和低廉的运营成本。这三种原因都能帮助解释为何能源价格低，但是政府补贴却必不可少。
单选题     What is the dirty secret of green energy? ______
 
【正确答案】 D
【答案解析】由题干中的the dirty secret of green energy定位至第二段第四、五句。 细节辨认题。第二段提到发展绿色能源面临的问题。第四句提到，绿色能源有一个不让人喜欢的秘密。第五句进一步解释这个秘密，即绿色能源使用得越多，就能更多地降低任何能源发电的电力价格，故答案为D。
单选题     Why are policymakers unwilling to develop renewable energy? ______
 
【正确答案】 A
【答案解析】由题干中的policymakers unwilling to develop renewable energy定位至第三段第一句。 推理判断题。第三段介绍，在一些地区，随着政府补贴的减少，对可再生能源的投资也减缓了。第一句指出，政策制定者已经看到这个棘手的事实，并以此作为理由来阻碍可再生能源。其中，this inconvenient truth指的是第二段最后一句——除非市场被固定化，对这个行业的补贴只会不断增加。由此可知，政策制定者因为补贴过高而不愿意发展可再生能源，故答案为A。
单选题     What can be done to make better use of green energy? ______
 
【正确答案】 C
【答案解析】由题干中的make better use of green energy定位至第三段最后一句。 推理判断题。第三段前两句指出，政府因不愿意投入补贴而阻碍绿色能源的发展。第三、四句笔锋一转，指出解决问题的办法不是少用风能和太阳能，而是应该重新思考如何定价，以更好地利用绿色能源，故答案为C。
单选题     What is the problem with renewable energy in nature? ______
 
【正确答案】 A
【答案解析】由题干中的the problem with renewable energy in nature定位至第四段第一句。 细节辨认题。第四段探讨了可再生能源面临这些问题的原因。第一句开门见山地指出，本质上来说，问题在于政府扶持的可再生能源被强加于一个在不同的时期设计的市场上。随后进行了分析。由第一句可知，可再生能源的本质问题是市场是在不同的时期设计的，故答案为A。